PROJECT SUMMARY Many biochemically interesting molecules, including the inhibitory and excitatory neurotransmitters GABA and aspartate, the redox compounds glutathione and ascorbate, and the neuromodulator N- acetylaspartylglutamate can be measured in the human brain non-invasively using edited 1H magnetic resonance spectroscopy (MRS). Until very recently, edited MRS has been applied as a single-metbaolite single-voxel method ? i.e. requiring a 10-minute acquisition to measure GABA, and additional experiments to measure other metabolites. This has substantially limited the breadth of application of edited MRS in clinical studies, and particularly studies of, for example, interactions between different systems. The overall goal of this grant is the development of a universal acquisition and processing pipeline for measuring levels of all these editable metabolites in the human brain from a single experiment. We will develop a single sequence, implemented on all three major vendor platforms, for multiplexed editing 3T, the Gannet Toolkit for quantitative data analysis, and demonstrate the cross-platform equivalence of the new measurement. The resulting data acquisition and analysis tools will be made available for dissemination to the clinical neuroscience and neuroimaging communities.